This invention relates to small hand-held dispensers involving pump assemblages, as distinguished from pressurized aerosol containers and valves. In the past there was proposed a press-fit closure assemblage for a pressurized aerosol container, as described and claimed in U.S. Pat. No. 2,957,611 issued to Philip H. Sagarin on Oct. 25, 1960. The plastic closure member disclosed therein was characterized by very thick walls whereby there was entailed a relatively long curing time and therefore a lengthy molding cycle. In cases where special reinforcement was mot utilized, previous efforts to reduce the required curing time by making the walls somewhat thinner frequently yielded unsatisfactory results in that there was a pronounced tendency for such closures to develop vertical cracks in the peripheral walls, as when the closures were forced onto or snapped over the rim of the container. Moreover, the tendency for the plastic material to shrink with aging meant the possibility of pressure leakage of the contents of the can during shipping or after a lengthy period of shelf storage.
To my knowledge no previous constructions have been proposed for economically assembling a pumping unit to an aerosol-type can of the kind capable of containing pressurized product, such as that normally sealed by a crimped closure as distinguished from screw threads. Nor were there any previous constructions for economically assembling pumping units to snap-closure type glass bottles. Instead, prior pump-type dispensers generally utilized threaded caps, and plastic or glass containers having cooperable threaded necks. These dispensers had the disadvantages of high cost of the screw threads as well as the relatively complex assembly machinery for attaching the screw caps and pumps to the threaded container necks.